/// <summary>
/// Encode an array of data codeword with GaloisField 256.
/// </summary>
/// <param name="dataBytes">Array of data codewords for a single block.</param>
/// <param name="numECBytes">Number of error correction codewords for data codewords</param>
/// <param name="generatorPoly">Cached or newly create GeneratorPolynomial</param>
/// <returns>Return error correction codewords array</returns>
internal static byte[] Encode(byte[] dataBytes, int numECBytes, GeneratorPolynomial generatorPoly)
{
int dataLength = dataBytes.Length;
Guard.NotNull(nameof(generatorPoly), generatorPoly);
if (dataLength == 0)
{
throw new ArgumentException("There is no data bytes to encode.");
}
if (numECBytes <= 0)
{
throw new ArgumentException("No Error Correction bytes.");
}
int[] toEncode = ConvertToIntArray(dataBytes, dataLength, numECBytes);
Polynomial generator = generatorPoly.GetGenerator(numECBytes);
Polynomial dataPoly = new(generator.GField, toEncode);
PolyDivideStruct divideResult = dataPoly.Divide(generator);
int[] remainderCoeffs = divideResult.Remainder.Coefficients;
return(ConvertTosByteArray(remainderCoeffs, numECBytes));
}
private void TestOneCase(int[] aCoeff, int[] bCoeff, int[] expQuotient, int[] expRemainder)
{
GaloisField256 gfield = GaloisField256.QRCodeGaloisField;
Polynomial apoly = new Polynomial(gfield, aCoeff);
Polynomial bpoly = new Polynomial(gfield, bCoeff);
PolyDivideStruct pds = apoly.Divide(bpoly);
int[] quotient = pds.Quotient.Coefficients;
int[] remainder = pds.Remainder.Coefficients;
if (!PolynomialExtensions.isEqual(quotient, expQuotient))
{
Assert.Fail("Quotient not equal. Result {0}, Expect {1}", aCoeff.Length, bCoeff.Length);
}
if (!PolynomialExtensions.isEqual(remainder, expRemainder))
{
Assert.Fail("Remainder not equal. Result {0}, Expect {1}", remainder.Length, aCoeff.Length);
}
}
